How severe is CVE-2017-16944?

CVE-2017-16944 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2017-16944 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 63% (99th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-16944?

CVE-2017-16944 primarily affects Exim. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2017-16944?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2017-16944 published?

CVE-2017-16944 was published on 2017-11-25 and last updated on 2026-06-17.

CVE-2017-16944

CVE-2017-16944 is a high-severity vulnerability in Exim with a CVSS 3.x base score of 7.5. Its EPSS exploit-prediction score of 63% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-835.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 63% (99th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-835
Affected product: Exim
Published: 2017-11-25
Last modified: 2026-06-17

Description

The receive_msg function in receive.c in the SMTP daemon in Exim 4.88 and 4.89 allows remote attackers to cause a denial of service (infinite loop and stack exhaustion) via vectors involving BDAT commands and an improper check for a '.' character signifying the end of the content, related to the bdat_getc function.

Frequently asked questions

What is CVE-2017-16944?: The receive_msg function in receive.c in the SMTP daemon in Exim 4.88 and 4.89 allows remote attackers to cause a denial of service (infinite loop and stack exhaustion) via vectors involving BDAT commands and an improper check for a '.' character signifying the end of the content, related to the bdat_getc function.
How severe is CVE-2017-16944?: CVE-2017-16944 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2017-16944 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 63% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-16944?: CVE-2017-16944 primarily affects Exim. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2017-16944?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2017-16944 published?: CVE-2017-16944 was published on 2017-11-25 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:exim:exim:4.88:*:*:*:*:*:*:*
cpe:2.3:a:exim:exim:4.89:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

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